When constructing large asphalt paved parking areas for large shopping malls or other purpose, such as road work, it is often mandatory to construct drainage areas and retention ponds for collecting rain water as the earth under the pavement no longer absorbs and filters water causing water to accumulate in areas adjacent to the pavement. Such retention ponds connect to associated infrastructure to direct water thereto. It is essential to conform to city regulations where storm water management is in place. In order not to oversupply storm sewers with accumulated water from large paved parking areas, there is required the construction of rain water storage basins. The water in these basins is released in the sewer system in a controlled manner. These infrastructures are very costly and require land utilization for the construction of these water retention basins which adds to costs and further reduces land usage for parking or other structures.
Another disadvantage of large paved areas is that the pavement, which is usually asphalt, produces excess heat when exposed to the sun and often this heat infiltrates into the adjacent building structures and therefore more energy is necessary to cool these structures. Further, because the asphalt does not conduct water it will accumulate water in depression areas thereof and this is a nuisance to the users of the parking spaces. Still further, because parking areas are used by automobiles, there are gasoline or oil spills on the asphalt as well as rubber marks from the automobile tires and these will contaminate the water which is channeled to the retention basins and released in the city waterworks, streams, and rivers. They could also pollute drinking water. The asphalt itself also produces undesirable chemicals which dilute in water and add to the above pollutants. Asphalt also cracks and heaves when water infiltrates into its sub-surface and freezes, making the asphalt surface unsightly and hazardous.
It is also well known in the art to construct paving surfaces, such as driveways in residential developments or elsewhere with precast concrete paving stones. These stones are usually laid side-by-side and some of these stones have peculiar interlocking shapes that mesh with one another to interlock to prevent lateral displacement. These paving stones are also installed on aggregates which have fines in it to form a compact upper surface to support the paving stones. The stones are usually in close side-by-side contact to prevent water to seep between the stones not to disturb the aggregate foundation. However, when vehicles are displaced over these paving stones, often the stones will separate from one another due to lateral twisting force applied thereto, such as when a vehicle tire turns on the surface of a stone, as each of these paving stones are not interconnected together in the vertical plain. Because these stones are not connected in the vertical plane, i.e., do not form a monolithic structure, with the constant displacement of heavy traffic thereon, the paving surface does not remain perfectly flat and depressions form therein making it unsightly. Also, when there are depressions, the top side edge of some of the blocks will be exposed or lie above adjacent blocks. Such exposed block edges are hazardous to people who can trip over these edges. Also, in cold climates subject to snow, the pavement is often damaged by snow plows wherein the plow catches these edges and often causes considerable damage to the pavement requiring expensive repair.
In an attempt to overcome the above-mentioned problems, some paving areas are constructed of aggregates of different stone size mixtures and this results in a pavement which has an unstable surface, which produces dust and which requires maintenance for maintaining a uniform surface. Such aggregate parking areas are also damaged by snow removal equipment. Fines in the aggregate will prevent water to percolate through the surface and potholes will form. Permeable pavements constructed of aggregate have not been popular and are not a viable solution to the above-mentioned problems.
An advantage of a paved surface constructed with the precast interconnectable concrete paver blocks of the present invention is that it forms a monolithic structure wherein the top surface of the blocks lies in common flat plane with the blocks interconnected together side-by-side. The blocks are also spaced from one another and form open-joint areas for water to seep to its support bed to form a permeable surface for water to percolate through its aggregate permeable bed. With the interconnectable concrete blocks of the present invention, portions of the surface can be easily disassembled, for example for running underground piping for wiring after the paved surface is constructed or the placement of heating cables or conduit whereby a portion of the surface, particularly close to an entrance of a supermarket, needs to be heated to melt snow and ice. Conventional paved surfaces formed of asphalt require heavy machinery to dig ditches to install any underground piping or wiring and this is very costly. Also, the trenches dug by these excavators also need to be refilled and re-asphalted and this forms irregular surfaces developing cracks and depressions which accumulate water and create failure in the aggregate base below the pavement.